Collapsing tap



E. M. BUCKIUS.

COLLAPSING TAP.

APPLICATION FILED AUG. 18. I9

1,344,1 13. PatentedJune 22,1920.

3 SHEETSSHLE1 l.

INVENTOI'Q JWO'PZ MBllc/zuus,

A TTORNE Y E. M. BUCKIUS.

COLLAPSING TAP.

APPLICATION FILED AUG.I8,1919.

3 SHEETS-SHLE] 2.

Patented J 11116 22, 1920.

WITNESSES INVENTOR Que/h ATTORNEY E. M. BUCKIUS.

COLLAPSING TAP.

APPLICATION FILED AUGJB, I919.

Patented June 22, 1920.

3 SHEETS-H113 WI TNESSES Y 4 w f ATTORNEY UNITED STA E-s EDWARD M. BUCK IUS, on Los ANGELES, CALIFORNIA.

COLLAPSING TAP. I

Specification of Letters Patent.

Patented June 22, 1920.

Application filed August 18, 1919. Serial No. 318,185.

new and useful Collapsing Tap, of which the following is a specification.

My invention relates to improvements in' collapsing taps and has more particular relation to the class of taps shown and described in the United States Letters Patent No. 832,716, issued to me October 9, 1906. In general terms, these taps comprise a body portion having a shank suitably formed for cooperative connection with the driven element of any desired type of machine tool and a plurality of radially movable tap dies which are engaged and translated by a manually operated actuator to present said dies to a definite tap diameter, the operation of the actuator storing energy in a normalizing spring, operativeto automatically normalize the dies upon a release of the actuator. p I

An object of the present invention is to provide a collapsing tap in which the radially movable dies are positively propelled outwardly to apredetermined tap diameter by a manually operated actuator and are automatically normalized by an independent means.

Another object is to provide an independent normalizing means for the dies which engages the dies at their longitudinal medial portion, providing a true transverse transmitting movement as distinguished from a movement having a torsional binding influence upon the dies.

A further object is to provide a tap of the above described type having a plurality of reaming cutters clamped in grooves in a disk secured to the end or nose of the tap, the disk and the body of the tap having intermeshing abutments preventing relative rotation and relieving the securing bolts of shearing strains. 7

Another object is to provide a chamfer device adapted to ohamfer the inner peripheral edge of the .work during the final portion of the'tapping operation and before the collapsing of the tap.

Another object is to combine the chamfer device with a trip device for the die actuator,so arranged as to provide a positive 7 sequence of operations, first, the chamfering to a definite depth and then the tripping operation. A further object is to provide means permittingthe chamfer device to operate uniformly on uneven surfaces of rough castings. i With these and incidental objects in view the invention consists incertain novel features of construction and combination of parts,the essential elements of which are set forth in the appended claims and a preferred form of embodiment of which is hereinafter described with reference to the drawlngs which accompany and form part of this specification. 1

In the drawings corresponding reference characters denote corresponding parts throughout the several views, of which:

' Figure 1 is a side elevation of the tap.

Fig. 2 is an end elevation.

Fig. 3 is a section on line w w of Fig. 4.

Fig. 4- is a section on line mw, of Fig. Fig. 5 is a section on line a0 w of Fig. Fig; 6 is a section on line ww, of Fig. Fig. 7 is a section on line ww, of Fig. Fig. 8 is a side elevation similar to Fig.

but looking from a different angle.

Fig. 9 is a section on line 0: re", of Fig. 8.

Fig. 10 is a section on line m w of Fig. 8.

' Fig. 11 is a detail side elevation of the chamfering and trip device. I

I Fig. 12 is an end elevation of Fig. 11.

Fig. 13 is a detail perspective view of the chamfer tool.

Fig. 14 is a partial side elevation showing a modified form of trip device.

Referring to the drawings, 1 designates the shank of the tap, and 2 the body or die holding member thereof which is preferably cylindrical. The lower end of the body 2 is recessed to form a cylindrical axial chamber 3 in which is contained the various operating parts and the wall of said chamber is provided with a plurality of radial slots 4. Slidably retained in these slots are a plurality of tap dies 5, the inner ends of which project into the chamber 3.

'A plate or disk 6, secured by'screws 7 to the bottom surface of the body, serves to carry the reaming cutters 8 and to close the lower ends of the chamber 3 and slots 4. The cutters are seated in radial grooves in the disk 6 and are clamped thereto by an end plate 10. These cutters are located closely adjacent the tap dies and serve to ream the hole just in advance of the tap dies during the same operation with the tapping of the hole. To concentrically aline the disk 6 upon the body 2 and also to relieve the screws 7 of shearing strains incident to a reaming operation I provide the disk andbody with intermeshing surfaces. As shown in Figs. 5 and 9, the body 2 is )rovided with sector rooves 11 se arated by. abutment webs 12. The disk 6 has a central boss 13 and a concentric bead spaced therefrom and notched to form sector ribs 14. providing abutment surfaces 15--15.

1 When the parts are assembled the, boss 13 extends into and closely fits the chamber 3 and the ribs 14 engage into the grooves 11 with the abutment surfaces 15-15 closely engaging the abutment webs 12 of the body. The boss 13 and ribs 14 have radial notches of greater width than the thickness of the tap disk to provide clearance therefor.

It will be seen that with thi construction, the boss 13 and intermeshing sector grooves 11 and ribs 14, the cutter disk 6 willbe retained in perfect concentrieity with the body and that the intermeshing abutment surfaces 15 15 and webs 12 will prevent relative rotary movement of the parts and relieve the screws of shearing strains.

An'oscillatory actuator 17 is journaled in the body 2 andthe disk 6 and is provided with a plurality of cam projections 18 each adapted to engage and translate its respective tap die 5. The longitudinal continuity of each of these cam projections is interrupted by a medial groove 19 (see Fig. 4) to provide clearance for a die normalizing spring, to be later described. In the preferred form as shown, the cams are of two part construction, the upper half thereof being integral with the actuator and the lower half being in the form of a collar having a spacing hub 20 and fitting a squared portion of the lower end of the actuator. This construction promotes a convenient assembling of the tap but for the purpose of this disclosure may be considered as of integral formation. j

A normalizing spring 21 (see Figs. 4 and 7) extends through apertures 22 in each die 5 and is joined together to form an endless coil spring of circular formation. Adjacent the spring and 011 each side of each die slot 4, thebody 2 is recessed as at 23 to providefor an outward flexing of the spring, as shown in'Fig. 7, when the dies are propelled outwardly by the actuator. It will be evident that when the actuator is returned to outwardly. This normal position, the spring 21 will assume its normal concentric form thereby returning the dies to their normal inner position.

By reference to Fig. '7 it will be noted that the recesses 23 are so formed that the walls of the chamber provide intermediate abutments which prevent a radial expansion of the spring between the recesses and that only those portions of the spring immediately adjacent said recesses will be flexed structure confines the spring between the dies against radial move ment whereby the inherent tension is utilized to a greater extent enabling the use of a much lighter spring than would be required if the entire spring could flex radially.

An operating handle 25 engages the upper squared shank portion of the actuator and extends outwardly through a slot in the body and between the handle and the cam projections 18 I provide a flat coiled spring 26 having one end attached to the body 2 and the other end to a collar engaging the squared shank of the actuator. During a die setting movement of the actuator, energy will be stored in the spring 26 for the purpose of normalizing the actuator when the handle is subsequently released.

Referringto Figs. 1, 4 and 8, 3O designates a sleeve cireumferentially adjustable around the upper portion of the body 2 and clamped thereto in adjusted position, by bolts 31 and plate 32. This sleeve is provided with a way 34 upon which is slidably mounted a latch plate 35 having an abutment edge'36 serving to limit the throw of the operating handle 25 and a hook projec tion 37 adapted to engage over said handle, retaining it in set position until released by an upward movement of the latch plate.

' A stop screw 38, engaging into an elongated groove 39 in the way 34, serves to limit the downward movement of the latch plate.

As the tap is usually operated in a vertical position, the weight of the plate 35 together with the frictional resistance of its slide way is ordinarily sullicient to yieldingly retain said plate in latching position.

Means are provided for lifting the latch plate atthe completion of the tapping operation thereby releasing the operating handle and connected die actuator. This latch tripping means comprises a slide block 40'longitudinally movable in a way 41 in the body 2 and provided with a work engaging surface 42 and a trip plate 43 adjustably secured thereto by a bolt 44 engaging through an elongated slot in said plate. A chamfering tool 45 is positioned ina groovein one-side of the block 40 and is clamped thereto by a clamp bolt 46, an adjusting screw 47 being provided for adjusting the tool. Seated in the upper end of the trip plate 43 is a spring 48 which engages the lower ed e of the latch plate 35 allowing a slight in ependent reciprocatory. movement of the trip device. This is possible by reason of the fact that the strength of the spring 48, while sufficient to reciprocate the combined strip and chamfering device, is not sufiicient to overcome the weight and frictional resistance of the latch plate 35. Therefore it will be evident that the latch plate will not be translated to release the operating handle until the trip plate 43 forcibly engages said latch plate. I

The manualsetting and automatic operations of the tap will now be explained in sequence. The reaming cutters 8 are clamped in position to ream the hole to a proper tapping'size. The sleeve 30 is circumferentially adjusted on the body to angularly define the limit of setting movement of the operating handle. This provides a definite setting movement of the die propelling cams of the actuator and definitely controls the tap diameter. If 'desired, the sleeve andbody may be provided with scale markings indicative of various settings of the sleeve. The handle and actuator, as a unit, is now oscillated and latched in position by engagement of the latch plate 35 with the handle. This operation propels the tap dies 5 outwardly to a. definite tap diameter. The tap then is .engaged with the work in a reaming and tapping operation.

During the final portion ofthe tapping operation it is desirable to chamfer the edge of the tapped hole and to this end the combined tripping and chamfering device is so located as to cause the chamfering tool to engage the inner peripheral edge of the work so as to properly, chamfer the work before a collapsing of the tap and as the rim of the casting may be of uneven contour it is desirable that the movements of the chamfering tool conform to said uneven contour. This is provided for by the spring 48 which maintains the chamfer tool in cutting contact with the work while at the same time providing for a slight independent reciprocation thereof allowing it to accommodate itself to any undulations of the surface of the work. After the chamfering is completed, the work engaging surface 42 engages the work, the trip device is forced upwardly relative to the tap body and the trip plate 43, engaging the latch plate 35, functions to unlatch the operating handle. The normalizing spring 26 returns the released actuator 17 allowing the die normalizing spring 21 to draw the dies into the tap body. It has been found that the spring 21 may be of relatively light tension because as soon as the cam projections of the actuator are removed from the inner edges of the dies the work tends to force the dies inwardly. This return of the dies is more gradual than the snap return of the actuator thereby producing a gradually diminishing thread out free from tool marks.

The modified form of trip shown in Fig. 14 may be utilized at times when it is not desired to chamfer the work and although ing handle much in the same manner as previously described in connection with the combined trip and chamfer device.

While I the form of mechanism herein shown and described, is admirably adapted to fulfil the objects primarily stated, it is to be understood that it is not intended to confine the invention to the one form of embodiment herein disclosed, for it is susceptible of embodiment in various forms, all coming within the scope of the claims which follow.

I claim:

1. Acollapsing tap comprising a body, a plurality of radially movable tap dies, an oscillatory actuator manually operated to translatethe dies outwardly, a latch device for retaining the actuator in operated position, means for tripping said latch device, a chamfering tool carried by said trip means, means forautomatically normalizing the actuator, and an independent means for normalizing the dies.

2. A collapsing tap comprising a body, a plurality of radially movable tap dies, an oscillatory actuator manually operated to translate the dies outwardly, a latch device angularly adjustable on the tap body forminga stop abutment for limiting the throw of the actuator and operating to retain the actuator'in set position, means for tripping the latch device, a chamfering tool carried by said trip means, means for automatically normalizing the actuator, and an independent means for normalizing the dies.

, 3. A collapsing tap comprising a body, a plurality of radially movable tap dies, an oscillatory actuator normally operated to translate the dies outwardly, a latch device for retaining the actuator in operated position, a trip slide on the body, a chamfering tool carried by said slide, means for automatically normalizing the actuator, and an independent means for normalizing the dies.

4. A collapsing tap combining a body having a cylindrical axial chamber and reeessed to provide spring passages and inter mediate abutment surfaces, the Wall of said chamber being radially slotted adjacent the passages, dies slidable in said slots and hav ing transverse orifices aliiied with the passages, a die actuator in the chamber, and

a single spring member entrained through the several die orifices and adapted to engage the intermediate abutment surfaces to spring member against radial movement.

Signed at Les Angeles, 11th day of August, 1919-.

California, this EDVARD M. BUCKIUS.

. Vitnesses:

CLARENCE B. FOSTER E. G. BLAsnEL. 

